Field of the Invention
The invention relates to an actuator and to an exhaust gas recirculation valve, a wastegate or a variable turbine geometry device of a turbocharger comprising an actuator of this kind.
In the field of internal combustion engines, it is known to recirculate exhaust gas to the fresh air side as a function of the operating state in order to reduce fuel consumption and pollutant emissions. The associated valve may be provided in this connection with a tappet displaceable in translation or with a flap actuated by means of a lever, while it may be advantageous for the actuator to have a rotary drive. This applies in the same manner to wastegates and/or variable turbine geometry devices of exhaust gas turbochargers, adjustable by means of a tappet displaceable in translation.
Description of the Related Art
An exhaust gas recirculation valve is known from EP 1 111 227 A2, in which the rotary motion of a drive is converted into a translational motion of the valve element. A rotary motion is imparted to the valve element at least at the start of the opening operation.
EP 1 526 271 A1 relates to an exhaust gas recirculation valve in which the rotary motion of a drive is converted into a reciprocating motion of the valve element, wherein the valve element may rotate with the drive element during the opening operation, but is not forcibly rotated therewith. The rotary motion is converted into a reciprocating motion essentially by means of a driven “screw” comprising a thread in engagement with a fixed, but rotatable wheel.